SailNet Community banner
1 - 20 of 24 Posts

·
Schooner Captain
Joined
·
2,199 Posts
Discussion Starter · #1 ·
So I have been wiring up my new generator, 3.5KW phasor, and I started thinking..
If I ever had a major leak The first system to go down would be 12 volt. the starter cannot be more then 12" from the bottom of the bilge. the batteries are just above that. So its a real chance if your taking on water, you may lose your 12 volt system. The plus side on our boat is our 120 volt is all run in the ceiling. The lowest part being the panel itself, 3' above the bilge.
My generator has a hand crank to start it, if the battery is dead, but if the 12 volt is down, it will not help to have it for the few minor things that run on 120volt. So why not have a 120 volt bilge pump, one, in case of major leaks, two, if you wake up to dead batteries, and have a leak of any kind?
I cannot be the first with this idea. Thoughts on the subject?
 

·
Registered
Joined
·
1,036 Posts
So I have been wiring up my new generator, 3.5KW phasor, and I started thinking..
If I ever had a major leak The first system to go down would be 12 volt. the starter cannot be more then 12" from the bottom of the bilge. the batteries are just above that. So its a real chance if your taking on water, you may lose your 12 volt system. The plus side on our boat is our 120 volt is all run in the ceiling. The lowest part being the panel itself, 3' above the bilge.
My generator has a hand crank to start it, if the battery is dead, but if the 12 volt is down, it will not help to have it for the few minor things that run on 120volt. So why not have a 120 volt bilge pump, one, in case of major leaks, two, if you wake up to dead batteries, and have a leak of any kind?
I cannot be the first with this idea. Thoughts on the subject?
It will work fine..
Get a submersible pump like one of these.
Submersible Utility Pumps | Water Pumps | Northern Tool + Equipment

It don't need to salt water resistant if you only intend to use it in emergency.
Store it out of the bilge water and drop it in where needed.
Make sure you have space to drop the pump down where it will get hold of water.

Around here pumps like these get used a lot in the spring when launching old wooden boats that tend to leak before wood starts swelling.
 

·
Registered
Joined
·
1,552 Posts
120 volt and rising water....with theoretical gnds...maybe none

humans involved...could cause some problems in keeping the two systems separated, as when they mix, generally the human loses
 

·
Schooner Captain
Joined
·
2,199 Posts
Discussion Starter · #4 ·
120 volt and rising water....with theoretical gnds...maybe none

humans involved...could cause some problems in keeping the two systems separated, as when they mix, generally the human loses
The 120 is so far above the bilge that the boat will be under before it hits the 120. The generator and the 120 panel are at the same level.
 

·
Registered
Joined
·
174 Posts
The main advantage of the 120 system is that it will move a greater volume of water and this sounds like a scenario where you are dealing with volume...
 

·
Master Mariner
Joined
·
9,225 Posts
We carry 3, 1/2 hp 110 volt ac submersible pumps (each pumps up to 2500 GPH), as well as several 12 volt bilge pumps. They attach to garden hoses, so we need no special hoses aboard, and if needed, they would also run off the inverter.
We would need about 7' of water aboard before it became a problem with the 110 volt service, and about the same for the 12 volt.
 

Attachments

·
Master Mariner
Joined
·
9,225 Posts
Well, if it's a 120 v submersible pump, your 120 v wiring will be in the bilge water.
Really, don't you think they are designed for that? They are not installed; they are portable.
 

·
Registered
Joined
·
233 Posts
You go ahead and stand in water with 120v wires in it. I'll watch.

I'd say when you are in dire straits with water over the floorboards and everything rolling and flying about, you don't need anything else to worry about.

Really, don't you think they are designed for that? They are not installed; they are portable.
 

·
Master Mariner
Joined
·
9,225 Posts
You go ahead and stand in water with 120v wires in it. I'll watch.
I really do not understand your concerns.The pump AND it's wiring are DESIGNED to go under the water, in other words, be SUBMERSIBLE. It would be pretty stupid to design a SUBMERSIBLE pump that wasn't safe to submerge, wouldn't it?
As for watching, I really doubt you and I would ever be on the same vessel, so that isn't any more logical than your fear of water around a SUBMERSIBLE pump.
 

·
Closet Powerboater
Joined
·
3,925 Posts
As a recovering wooden boat owner, I think, and have thought about bilge pumps, WAAAY too much. I have lots of experience with them as well since TWICE my hull ended up with 8foot cracks in it. And yes, they leak like a sive when first launched.

We used one of those 110v submersible pumps both times she was launched. Both times, she overwhelmed my 3 12V bilge pumps in a matter of a minute or two. They were a 2000GPH, 1000GPH and a 500GPH. BTW, this is a good time for me to plug Rule pumps. They are the only 12v pumps I will ever buy. They were reliable, and thrived on abuse and never ever failed, though many other brands I tried did.

I've been thinking along the exact same lines you have been recently, though I honestly hadn't thought about the direct connection to the generator. I was thinking of using an inverter, but bagged the idea because it involved too much complexity and not enough redundancy.

Another advantage of the system you mention is that you can keep some really large (2-3" diameter) hose all coiled up and ready to go and run it outside when needed. That way you don't need to drill such a large hole in your boat either. You really do want large discharge lines. The GPH ratings go downwards very quickly as the hose gets smaller.
http://www.northerntool.com/shop/tools/NTESearch?escapeXml=false&ipp=24&storeId=6970&Ntt=water%2Bpump%2Bhose


I definitely think the idea has merit.

MedSailor
 

·
Registered
Joined
·
233 Posts
You are right that they are designed to be under water. But things can happen, and WE are not designed to be in water where there might be stray 120 v. I can take some comfort that, as I understand it, it wouldn't be as dangerous in the salt water I sail in.

We already have 12v on the boat, so why not play it safe? I have 2 X 4000 gph pumps (I think; they have 2" hoses, anyway), so capacity is available. I just have to run bigger wires than you do.

But to each his own. I just have a healthy respect for high voltages.

I really do not understand your concerns.The pump AND it's wiring are DESIGNED to go under the water, in other words, be SUBMERSIBLE. It would be pretty stupid to design a SUBMERSIBLE pump that wasn't safe to submerge, wouldn't it?
As for watching, I really doubt you and I would ever be on the same vessel, so that isn't any more logical than your fear of water around a SUBMERSIBLE pump.
 

·
Bristol 45.5 - AiniA
Joined
·
4,525 Posts
Will let others talk about the pump. One comment about the hand crank for the engine. Those things are surprisingly hard to use since you can't typically stand in a good location to get your weight into the cranking as you could if cranking a car (God, I must be old I had a car with a hand crank!). On a boat I have found it to be a two person job since once person needs both hands to crank while the other person is needed to flip the decompression switches down at the magic moment. I did it once singlehanded by running a light line from a decompression switch through some blocks to a loop around my head (don't ask). It actually worked.

What I am saying is make sure that you can hand crank and would be able to do if the boat was bouncing around before spending a bunch of money on a system that might rely on hand cranking.
 

·
Closet Powerboater
Joined
·
3,925 Posts
What Killarney says is true. I got pretty good at hand cranking my yanmar but it was a steep learning curve and I always used 2 people as he says. Never needed to engineer a one person method but it would take creativity.

Brevity and typos are courtesy of my Samsung S4 Active.
 

·
Registered
Joined
·
709 Posts
I keep a 120V sump pump connected to my shore power. It has a large capacity and for back-up and a leak that would exceed the capacity of the 12V pump. I test it periodically running water into the bilge. Works fine.
 

·
Closet Powerboater
Joined
·
3,925 Posts
I imagine a high output pump could also be used as an emergency firefighting device. Then, it could be used to de-water the boat once the fire is out.

MedSailor
 

·
Registered
Joined
·
277 Posts
I keep a 120V sump pump connected to my shore power. It has a large capacity and for back-up and a leak that would exceed the capacity of the 12V pump. I test it periodically running water into the bilge. Works fine.
This is another advantage of a 120 v pump, you can run it off shore power at the dock. I once read more recreational boats sink at the dock than at sea. Even with 12v system active, if the leak starts when you are away from the boat for a few days the batts will not be enough.
 

·
Registered
Joined
·
4,721 Posts
When the attending CG couldn't get their gas powered pump to go I showed up with my portable 110 sump pump . 40 footer nearly at her deck with fresh water from the city water supply (go figure) Never used my multiple systems (3 big Rules and a 2 inch engine driven which could connect to 150 feet of fire hose) on my own vessel but the portable was often handy for dewatering skiffs .With care and good wiring never a tingle (twitch)
 
1 - 20 of 24 Posts
Top